Abstract of Dissertation Presented to the Graduate School
 of the University of Florida in Partial Fulfillment of the
 Requirements for the Degree of Doctor of Philosophy

 CONTRIBUTIONS OF THE INDIVIDUAL b SUBUNITS TO THE FUNCTION OF
 THE PERIPHERAL STALK OF F1Fo ATP SYNTHASE

 By

 Tammy Weng Bohannon Grabar

 August 2004

Chair: Brian D. Cain
Major Department: Biochemistry and Molecular Biology

 The universal molecule of biological energetic is adenosine triphosphate (ATP),

and the enzyme involved in providing the maj ority of cellular ATP is F1Fo ATP synthase.

Enzymes in this family utilize the electrochemical gradient of protons across membranes

to synthesize ATP from ADP and inorganic phosphate in a coupled reaction. The

cytoplasmic Fl and the membrane-bound Fo sectors are linked by two stalk structures, the

rotor stalk and the peripheral stalk. Proton conduction through the Fo sector drives the

rotation of the rotor stalk within the catalytic core, which is held steadfast by the

peripheral stalk. In Escherichia coli, the 6 subunit of F1 and a parallel homodimer of

identical b subunits constitute the peripheral stalk of F1Fo ATP synthase. Work

accomplished in this dissertation indicates that the bacterial enzyme does not require two

identical b subunits to form the dimer. Two different length b subunits, with a size

difference of at least 14 amino acids, were capable of forming the b dimer of an intact

F1Fo ATP synthase complex. Also, in work presented in this dissertation, a defective